AB0263 FAT AND LEAN MASS DISTRIBUTION USING DUAL ENERGY X-RAY ABSORPTIOMETRY (DEXA) IN PATIENTS WITH RHEUMATOID ARTHRITIS AND ITS RELATIONSHIP TO DISEASE SEVERITY
Authors: M. Malik, P. S Kumar, A. Kumar P H, M. Gopalakrishnan, R. Shukla, M. K. Garg
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Obesity and sarcopenia have been associated with higher disease activity, poor response to disease modifying agents and lower remission achievement in rheumatoid arthritis (RA) patients [1, 2]. Weight loss has been associated with increased chances of remission [1]. The prevalence of obesity in the Asian population is 64% but the relationship between fat distribution and disease activity is not explored in the Indian population [3]. <h3>Objectives</h3> To describe fat mass, lean mass, fat mass index, lean mass index, fat mass percentage, fat-to-lean mass ratio, android-gynoid ratio and trunk-leg fat ratio measured using dual energy x-ray absorptiometry (DEXA) in patients with rheumatoid arthritis and assess their relationship with DAS28, patient global assessment of disease activity (PtGA), and Indian health assessment questionnaire (IHAQ) disability index. <h3>Methods</h3> A hospital based cross-sectional study was initiated after Ethics Committee approval in patients with RA at our rheumatology clinic from March 2022 onwards, at Jodhpur, India. Demographic, clinical, anthropometric and treatment details of the patients were collected after informed written consent. Whole body DEXA was done using a DEXA scanner Hologic Corp, model no - Horizon A S/N 303237M). Correlation of fat mass, lean mass, fat mass index, lean mass index, fat mass percentage, fat-to-lean mass ratio, android-gynoid ratio and trunk-leg fat ratio with DAS28, PtGA, and IHAQ was determined using Spearman correlation. Multivariable logistic regression was done to see if fat distribution indices could predict disease activity and IHAQ disability index. This is an ongoing study, with a calculated sample size of 104. <h3>Results</h3> Sixty patients have been enrolled so far with a mean age of 46 ± 11 years, 78.3% were females. Mean body mass index was 23.7 ± 5.1 kg/m<sup>2</sup> and 51.7% (n = 31) patients were overweight. Mean waist-hip ratio was 0.88 ± 0.07 among females and 0.98 ± 0.08 among males. The mean fat mass percentage, lean mass index, fat lean mass index, android-gynoid ratio and fat trunk-leg ratio were 39.87 ± 6.13%, 14.46 ± 2.31 kg/m<sup>2</sup>, 67.19 ± 19.26, 0.92 ± 0.14 and 0.81 ± 0.12 respectively. The median fat mass, lean mass and fat mass index in the study population were 22.98 ± 10.42 kg, 33.53 ± 10.42 kg and 10.05 ± 4.19 kg/m<sup>2</sup> respectively (Table 1). The fat mass percentage had significant correlation with previous history of steroid use for more than 21 days (r = 0.347, p = 0.008). None of the fat distribution indices evaluated could reliably predict DAS28, PtGA, and IHAQ disability index using multivariable logistic regression models. <h3>Conclusion</h3> The proportion of patients who were overweight was less in our patients with RA compared to the general population [3]. In this ongoing study, body fat composition and distribution did not exhibit any relationship with disease severity, or disability. However, prolonged steroid use increased fat mass percentage. Further studies are needed to evaluate the changes in fat and lean mass distribution and their relationship to disease activity. <h3>References</h3> [1] Moroni L, Farina N, Dagna L. Obesity and its role in the management of rheumatoid and psoriatic arthritis. Clin Rheumatol. 2020 Apr;39(4):1039–47. [2] Son KM, Kang SH, Seo YI, Kim HA. Association of body composition with disease activity and disability in rheumatoid arthritis. Korean J Intern Med. 2021 Jan;36(1):214–22. [3] Marwaha RK, Tandon N, Garg MK, Narang A, Mehan N, Bhadra K. Normative Data of Body Fat Mass and Its Distribution as Assessed by DXA in Indian Adult Population. J Clin Densitom. 2014 Jan 1;17(1):136–42. <h3>Acknowledgements</h3> None. <h3>Disclosure of Interests</h3> None Declared.